Control system for isotope separating apparatus



Jan. 26, 1960 s. w. BARNES CONTROL SYSTEM FOR ISOTOPE SEPARATING APPARATUS Filed Nov. 21, 1946 NW E m mm nu fv awe/Mun Sidney WBarnes.

Mfi M Ufli'v d S es Patent Y CONTROL SYSTEM FOR rsororn 'sE'PAR A TIN G p e APPARATUS Sidney. Bairies, Rochester, N.Y., assignor, by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission Application November 21, 1946, Serial No. 711,303

' i I 4 Claims. (Cl. 250-419) This invention relates generally to isotope separating apparatus of the electromagnetic type, commonly referred to as a calutron, and is more particularly concerned with improvements in methods of and means for controlling the position and condition of the ion beam of such calutrons formos't eflicient operation.

While,th e' apparatus of the present invention is not limited tothe separation of the isotopes of any one element, itmust of necessity be specially adapted for the masses involved, and in order for its principles to be clearly understood, the invention will be described as embodiedin apparatus adapted for the separation of the uranium isotopes having atomic weights 235 and 238, the isotope having an atomic weight of 234 being ignored.

In such calutrons, a beam of positive ions of uranium is formed and projected at a high uniform velocity into an evacuated region traversed by a substantially uniform magnetic field at right angles to the direction of motion of the ions. As a result, each particular ion is caused todescribe a circular path having a radius proportional to the square root of its mass. In this way the original single ion beam is split into two more or less distinct component beams, one of which consists of uranium ions having a mass of 238 and the other of which consists of uranium ions having a mass of 235. Because of a geometrical focusing action, these two beams are most distinctly resolved after the completion of 180 of their circular path, and the U and U ions may be separately collected at a receiver located at this point.

This invention is directed to the proper control of the position of the ion beams Within the calutron so as to insure most efiicient collection of the U isotope, and it is particularly applicable to the case where the charge material contains uranium in its natural or only slightly enriched state.

:When such charge material is used, it is the ordinary practice to employ a receiver having a single metered pocket" for the collection of the U beam and an adjacent metered electrode upon which the bulk of the U beam is allowed to fall, the centers of these respective receiving portions of the receiver being an arcurately predetermined distance apart to correspond with the theoretical separation attained between the U and U ion beams under'the predetermined operating conditions.

The prior method of centering the U beam accurate-' therefore, theoretically, atleast, that the U beam was centered over the U pocket.

This method worked well at the beginning of a run.

However, after a short period of operation, the effective distance between the centers of the U and U receiving.

portions 'of the'receiver becomes substantially altered.

This maybe due to expansion or warping of the structural" 2,922,882 Patented Jan. 26, 1960- former method of ion beam control, a more direct methodi.

- no part of the present invention, they have not been shown;

. :able under some circumstances to avoid so called space U pocket.

receiving portions of the receiver, and numerous other causes. As a result, there could be no assurance that; the U beam was centered over the U pocket even: though the U ammeter reading was a maximum.

To overcome the above-described disadvantage of the:

of centering the U beam over the U pocket was required, and this the present control system provides.. In accordance with the principles of the present inven-- tion, the U beam is first centered over the U pocket; the attainment of this condition being evidenced by at maximum reading on the U ammeter, and then the: whole ion beam is shifted by a predetermined amount sufficient to move the U beam over the center of the: A slotted door is pivoted into position; over the U pocket during the monitoring operation sot as to permit only a small, yet representative, portion of the U beam to enter the U pocket, thereby mini-- mizing contamination during monitoring of the material. collected in the U 5 pocket.

Accordingly, the primary object of the present inven-- tion is to provide a method of and means for correctly": positioning the ion beam of a calutron during operation.-

Another object of the invention is to provide a novel;

calutron receiver particularly adapted to facilitate thee correct positioning of the ion beam with respect to the: receiver.

A further object of the invention is to provide a mon itoring system for correctly positioning the ion beam of. acalutron, said system involving a minimum contamina-- tion ofthe separated material being collected.

Other objects and advantages will become apparent. from the specification taken in connection with the accqmpanying drawings wherein one embodiment of the: invention is illustrated.

In the drawings, Fig. 1 is a diagrammatic side elevational view, partly in section, of a calutron showing the novel receiver of the present invention.

Fig. 2 is a plan view of the slotted receiver door of Fig. 1.

Fig. 3 illustrates typical beam intensity patterns for the U and U ion beams in their correct space relationship withrespect to the receiver.

The arrangements shown in the drawing are in the main largely diagrammatic and consist of only those features necessary to a complete understanding of the invention. The various supporting structures and auxiliary equipment may take any form known to those skilled in the art. Since such structure and equipment constitute since doing so would serve only to obscure rather than, disclose the invention.

Referring now to Figs. 1 and 2 in particular, there is:

may take'place, and this vessel is preferably evacuated,:'

although the presence of a small amount of gas is desircharge efiects.

Within the closed vessel 10, and also within the region of influence of the magnetic field induced by the pole piece 11, there is provided a source 18 of positive ions of a charge material, such as uranium, the isotopesof which it is desired to separate. This source 18 of positive members-or the receiver at the high operating tempera ions has associated with it an accelerating electrode 19 which serves to project in a direction normalto the mag; ne'tic field a" stream or beam of high' velocity positiye j ions.

The accelerating. electrode 19 is grounded, as shown, and theio'ii source'18 is normally maintained at a position to the solid line position of Fig. 6, with such increasing imposition of force on the button as to,cause switch 20 to' close, the pump motor operates impeller 49 and the liquid level falls accordingly, the chamber 6'3 being subject to the suction at the intake of the impeller. Prior to this, the Chamber 63 ofthe control has been pressurized only upon a rise of the liquid level above the small port 68 in line 64.

As the liquid level falls .a partial pressure or vacuum condition becomes effective in chamber 63, which is not materially affected by the small bleede'r aperture 68, and this vacuum causes the diaphragm 14 to beheld in closing relation to the switch 20. The vacuum'is not reduced suflicie'ntly to enable the diaphragm to move away from the switch button and permit the switch to open untilthe level has dropped beneaththe intake, or impeller eye, end of the vacuum line 64. When this occurs, the vacuum in chamber 63' is immediately broken.

The provision of the auxiliary vacuum .line 64- is thus seen to constitute a simple and convenient means to materially lengthen the operating cycle of the motor and thus practically dry out the sump before the motor cycle terminates. The optional positioning of the small aperture 68 permits a desired variation in the differential pressurizing of the diaphragm 14 on its opposite sides; and the inverse size proportioning of the larger chamber 63 and smaller vacuum line 64 in relation to the smaller pressure chamber 61 and the larger pressure line 58 aflords a further means of timing the installation as to the institution and termination of motor operation.

7 In reference to Fig. 6, it may be noted that the diaphragm housing or casing 52 is here designed for disposition externally and to one side of a motor housing (not shown), and to this end, a spring clip 70 is aflixed to the casing 52 and may snap onto the usual shaft housing 71. However, it will be clear from the foregoing, and it is an important feature of the invention, that the housing or casing 52 need not be mounted to either the pump or its motor, but can be disposed in any convenient location, so long as its pressure tube 58 (and vacuum tube 64 also,

if employed) is brought properly into the sump. It follows as another advantage that no part of the housing need be immersed in the sump water.

The control illustrated in Fig. 6 may be, as indicated above, produced as a replacement or adapter unit, for which type of operation the unit has special utility due to certain wiring provisions hereinafter described. The in vention as embodied in Fig. 6 also contemplates a modi fication of the intake tube 53 to the pressurized side of the diaphragm housing or casing 52.

In accordance with this improvement, the tube 58 is, upon installation and proper location relative to the sump, flattened substantially at 58' over a length which will be determined in accordance with the particular installation, the length occurring intermediate the overall length of the tube 58. The outline of the tube, minus the flattened section 58', is shown in dot-dash line in Fig. 6.

Thus, as the sump water level rises, water will rise in the full diameter lower section of the tube 58 and, entering'the flattened section 58, its ability to compress air in the chamber 61, for a given increment of water level rise in the sump, is materially diminished. Thus. the interval before the diaphragm 14 operates to close switch 20 is increased, and the pump, comes into opera tion at a later time. The duration of this interval may be controlled by lengthening or shortening the flattened section 58, or varying its flatness or its location.

The control regulation may also be accomplished by a rotative adjustment of the tubular externally threaded mounting fitting 26 of switch 20, which fitting threads directly in a boss 53' of switch housing member 53 and is held by a lock nut 53" By this means the switch button 22 may be positioned variably in relation to diaphragm, thus to regulate the commencement and dura i tion of motorcycles, yet the axial alignment of the button and diaphragm remains unchanged.

In the unit illustrated in Fig. 6 the electrical leads 30 from the switch are brought out through the tubular threaded mounting fitting 26, preferably in the form of a conventional insulated cable 73 leading to a conventional electrical plug-in connector 74, and a type of female electrical socket member 75 is connected in the cable 73 with its socket terminals 76 wired in series with the plug 74- and switch terminals 31. Cable 73 may be of any desired length, so that in applying the control unit as a replacement, all that is necessary to do is to connect the existing electrical motor connector (not shown) of the sump pump in the socket 75, then plug the connector 74 in a suitable electrical outlet socket or box. It is not necessary to make any'par'ticular mount: ing for the control housing 52, and any support on which it maybe suspended will suflice. Tubes 58 and 64, if used, are brought to the sump as above described.

Fig. 7 illustrates an alternative type of regulatory provision in the intake tube 58 as a means for determining the cut-in and cut-out time of the pump motor in any particular installation. In this instance, the tube 58 is shaped in a spiral coil 59 of flexible tubing intermediate the top and bottom extremities of the tube. The coil isadapted to be elongated by stretching the same to form the intermediate axially distorted coil portion 60, which in the length of a single coil convolution or two will occupy an axial length much greater than the undistorted coil. Accordingly, a given rise of water level in the sump will be more effective, entering the lower coils 59 and effecting a greater displacement of air for a given liquid rise, than in the uncoiled length. It is then possible, by altering the overall length of the coiled section upon installation, by stretching out the portion 60, to set the motor cut-in and cut-out times as desired. The adaptation of Fig. 7 represents a reversal of the effect of the regulatory means shown in Fig. 6.

Fig. 8 illustrates a further modification operating on the principle of Fig. 7 to accomplish the foregoing purpose. In this instance, an adapter casing or chamber 62 is inserted in the intake tube 58, as'by connecting fittings 62' at the top and bottom of the casing. The enlarged volume of the latter occasions an increased compression of air in the pressure chamber 61, as water rises from the'lower end of tube 58 into the adapter casing 62, with a corresponding adjustment of the motor cut in and cut-out interval.

What'I claim 'as my invention is:

l. A control unit for a sump pump or like motor, comprising a housing having a flexible diaphragm subdividing its interior into pressure and switch control chambers on opposite sides of the diaphragm, an elongated liquid intake tube downwardly communicating said pressure chamber with a source of liquid to be pumped, a vacuum line to communicate said control chamber with the intake side of the pump, a switch disposed'in said control chamber 'for actuation by said diaphragm upon pressurization of said pressure chamber, said switch having an operating element facing said diaphragm and operated thereby under the eflects of pressure and vacuum in said respective pressure and control chambers, said switch being provided with a threaded mount disposed in coaxial alignment with said operating element, said threaded mount having threaded engagement with said housing for rotative adjustment to variably position said operating element relative to said diaphragm.

2. A control unit for a sump pump or like motor, comprising a housing having a flexible diaphragm subdividing its interior into pressure and switch control chambers on opposite sides of the diaphragm, a liquid intake member downwardly communicating said pressurejchamber witha source of liquid to be pumped, a vacuum -line to communicate said control chamber with the intake side of the pump, a switch "disposed in said ings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a calutron wherein the ion beam includes a first component beam formed of ions of a more abundant isotope and a second adjacent component beam formed of ions of a less abundant isotope, a calutron receiver adapted for the eflicient collection of the less abundant isotope, comprising a pocket or container for the receipt and collections of ions of said second component beam, said container having an elongated entrance slot through which ions are normally permitted to enter said container, and a door movable to a position over said entrance slot, said door having a series of slots, said series being aligned With said entrance slot for permitting a representative portion of ions to enter said container.

2. In a calutron wherein the ion beam includes a first component beam formed of ions of a more abundant isotope and a second adjacent component beam formed of ions of a less abundant isotope, a calutron receiver adapted for the efiicient collection of the less abundant isotope, comprising a pocket or container for the receipt and collections of ions of said second component beam, said container having an elongated entrance slot through which ions are normally permitted to enter said container, a blocking element movable to a position to cover said entrance slot, said element having a plurality of apertures therein for permitting a representative portion of ions to enter said container.

3. In a calutron wherein the ion beam includes a first component beam formed of ions of a more abundant isotope and a second adjacent component beam formed of ions of a less abundant isotope, a calutron receiver adapted for the efiicient collection of the less abundant isotope, comprising a pocket or container for the receipt and collections of ions of said second component beam,

said container having an elongated entrance slot through which ions are normally permitted to enter said container, an insulated electrode disposed adjacent said entrance slot for normally receiving ions of said first component beam, measuring means connected to said electrode for indicating the number of ions impinging thereon, and a door movable to a position covering said entrance slot, said door having a series of slots, said series being aligned with said entrance slot for permitting a representative portion of ions to enter said container.

4. In a calutron wherein the ion beam includes a first component beam formed of ions of a more abundant isotope and a second adjacent component beam formed of ions of a less abundant isotope, a calutron receiver adapted for the efiicient collection of the less abundant isotope, comprising a pocket or container for the receipt and collections of ions of said second component beam, said container having an elongated entrance slot through which ions are normally permitted to enter said container, an insulated electrode disposed adjacent said entrance slot for normally receiving ions of said first component beam, measuring means connected to said electrode for indicating the number of ions impinging thereon, a blocking element movable to a position to cover said entrance slot, said element having a plurality of apertures therein for permitting a representative portion of ions to enter said container.

OTHER REFERENCES Smythe et al., Physical Review, February 1, 1937, vol. 51, pages 178 to 182. 

